IDENTIFICATION AND QUANTIFICATION OF MONOHYDROXYBENZENES, DIHYDROXYBENZENES AND TRIHYDROXYBENZENES (PHENOLS) AT TRACE CONCENTRATIONS IN SEAWATER BY AQUEOUS ACETYLATION AND GAS-CHROMATOGRAPHIC MASS-SPECTROMETRIC ANALYSIS

A method is described that uses aqueous acetylation with acetic anhydr ide, solid-phase extraction (SPE) and concentration, and gas chromatog raphic-mass spectrometric (GC-MS) analysis to identify and quantify mo no-, di- and trihydroxybenzenes (phenols) at low concentrations in mar ine and waste waters. Phenolic compounds in water samples were buffere d with NaHCO3 and directly acetylated with acetic anhydride. Phenol ac etates were then extracted using C-18 SPE columns. The columns were el uted and the phenol acetates concentrated and analyzed by GC-MS. Detec tion of phenols in the ng 1(-1) concentration range can be obtained wi th 500 ml of sample. A large volume extraction setup is described from which detection limits in the upper pg 1(-1) range may be obtained. T he method was applicable to a wide range of phenolic compounds but was not suitable for nitrophenols. Water samples from several coastal env ironments and wastewater treatment facilities were analyzed for phenol s using this method. Phenol, cresols and catechols were the most commo n phenolic compounds identified. Concentrations ranged from 2.5 to 370 ng 1(-1) for these phenols in seawater sampled in San Diego Bay, in t he vicinity of White's Point outfall off San Pedro (Los Angeles area) and outfalls off the Northern coast of California near Eureka.